Grant Foster AAVSO, 25 Birch Street, Cambridge, MA 02138
Wayne M. Lowder* 511 Grasslands Road, Valhalla, NY 10595
Edward J. Oravec 104 Bella Vista Street, Tuckahoe, NY 10707
Abstract
Galactic cepheid variables have been studied both visually and
photoelectrically for decades. While photoelectric data are generally of high
precision, they are literally few and far between. Visual data are of lower precision,
but for many stars we have great quantities of data over a very long time span,
from which we gain useful information about their amplitudes, and can determine
periods with startling precision, enabling very detailed study of the stability of
cepheid periods.